This invention relates to a hammer tool with a drive motor and a hammer mechanism, said hammer mechanism including a drive piston reciprocably movable in a cylinder for driving a hammer piston towards a working tool releasably coupled to the front end of the hammer tool.
Hammer tools of that kind have been heavy and often unsymmetrically loaded which have made them uneasy to handle for the operator. According to one type of prior art tool the above disadvantage is reduced by directly driving the hammer piston by the motor piston both being movable in the same cylinder but this will on the other hand bring a drill hammer which runs irregularly and has a high production cost since the drive motor parts must be specially designed to fit in the unit thus excluding the use of serially manufactured standard motors.
An object of the invention is therefore to provide a portable hammer tool which is lighter and easier to handle than prior art tools but still having the same or better performance. Another object is to provide a hammer tool which can be driven by an exchangeable drive motor manufactured separately from the hammer mechanism. A further object is to provide a hammer tool which can be driven by interchangeable drive motors of different kind e.g. of combustion, electric or hydraulic kind.
It is still another object to provide a hammer tool which is compact and well silenced and matches all safety regulations set up for different motor alternatives.
These objects and others are achieved by providing a portable hammer tool according to the accompanying claims.